Fitness Function altenatives in Genetic Algorithms for game AI
Is this a viable replacement to the Fitness function?
  


Sure, the fitness is 1 for the winner and 0 for the loser. You're using some kind of the Tournament selection.

It might be better to use more chromosomes and let A play against B, C, D... and define the fitness as the number of wins. Or not, as such an evaluation is more precise but also more time-consuming.


  
  ... Infinity ... Do I also need to add this score to the chromosome?
  


Why should you? The exact value doesn't matter (as it only needs to be big enough), so there's nothing to evolve there. You don't represent the number  of players either, right? Just use common sense.


  
  ... Would it still be okay to generate chromosomes randomly?
  


I guess so, but a distribution providing values closer to the expected outcome should be better. This depends on how you mutate them (adding a small random value won't bring you far, multiplying by 1 + small_random_value would).

Alternatively, you can generate values from some fixed interval and scale them up.

Your values are IMHO far too big. Whatever your 5 and 40000 mean, I guess, that 5 and 400 would work the same.